Abrasive element for finishing paint brushes or the like



June 24, 1969 H. J. HAZEL-TON ABRAS IVE ELEMENT FOR FINISHING PAINT BRUSHES OR THE LIKE Filed Feb. 17. 1966 United States Patent 3,451,173 ABRASIVE ELEMENT FOR FINISHING PAINT BRUSHES OR THE LIKE Harold J. Hazelton, Batavia, Ill., assignor to Carlson Tool & Machine Co., a corporation of Illinois Filed Feb. 17, 1966, Ser. No. 528,122 Int. Cl. B241) 7/00, 9/00, 1/00 U.S. c1. 51-110 8 Claims ABSTRACT OF THE DISCLOSURE This application relates to the brushmaking art and more particularly to a new and improved abrasive element for use in finishing a brush.

In the art of manufacturing brushes, such as paint brushes or the like, there are several finishing steps which are performed on the bristles of the brush after the bristles have been assembled into the handle or back of the brush. After being so assembled, the bristles still present a rectangular configuration in Side elevation rather than being tapered as is desired with such brushes and still are too smooth for satisfactory painting performance. This invention is concerned with an apparatus and method for assisting in forming the tapered or chisled point on a paint brush.

It is a primary object of this invention to provide a new and improved abrasive element for finishing the free ends of brush bristles in a generally tapered configuration.

It is another object of this invention to provide a new and improved abrasive element for finishing the free ends of brush bristles wherein the abrasive element is provided with a configuration which progressively engages the bristles of a brush to an increasing depth while simultaneously progressively fanning the bristles out' in wider spread as the brush is moved through a linear path adjacent the abrasive element.

Yet another object of this invention is to provide a new and improved brush finishing station for a brush finishing machine provided with abrasive elements of this invention which are rotatably mounted on axes above the path of travel of an upright brush member and are provided with a brush engaging surface having a configuration for progressively engaging the free ends of the bristles of a brush.

A further object of this invention is to provide a novel method of finishing the bristles of a paint brush by feeding the bristles through a linear path and subjecting the bristles to a rotating tapered abrasive surface.

Yet a further object of this invention is to provide a novel method of finishing paint brush bristles by subjecting the bristle ends to a convex rotating abrasive surface, the path of brush travel being vertically displaced from the abrasive surface so that the peripheral edge of the disc is spaced above the free ends of the bristles.

Other objects, features and advantages of the present invention will be apparent from the following description of the preferred embodiments illustrated in the accompanying drawings, in which:

FIGURE 1 is a fragmentary front elevational view of a brush finishing assembly showing one station of the 3,451,173 Patented June 24, 1969 brush finishing assembly which utilizes the novel abrasive means of this invention;

FIGURE 2 is a bottom plan view of the abrasive element of this invention;

FIGURE 3 is a section view taken along the line 33 of FIGURE 2;

FIGURE 4 is a diagrammatic top plan view showing the relative positioning of the abrasive elements and the path of brush travel through the brush finishing station in which the abrasive elements of this invention are located and demonstrating the relative travel of the bristles and handle portion of the brush responsive to rotation of the abrasive element;

FIGURE 5 is generally a side elevational view diagrammatically sequentially showing a brush being fed past the surface of the abrasive element of this invention;

FIGURE 6 is a section view taken along the line 66 of FIGURE 4;

FIGURE 7 is a section view taken along the line 77 of FIGURE 4; and

FIGURE 8 is a section view taken along the line 88 of FIGURE 4.

Referring now to the drawings, in FIGURE 1 there is shown a portion of a brush finishing assembly such as is shown and described in greater detail in my copending application entitled Conveyor Apparatus, Ser. No..500,741, filed Oct. 22, 1965, now US. Patent No. 3,315,786, issued Apr. 25, 196 7. As described in the aforementioned application, the brush finishing assembly 10 supports finishing accessories such as 12a and 12b which are mounted on substantially identical frame units 14 thereby defining a plurality of different brush finishing stations depending upon the particular accessories 12a and 12b mounted on each of the units 14. As explained in the aforementioned application, the units 14 could be grouped into a continuous assembly so that brushes 16 could be continuously fed through the assembly and subjected to different finishing operations by several finishing accessories attached to each unit. It is to be further understood that the apparatus and method of this invention could be suitably employed in one unit 14 or other basic units, the structure shown in unit 14 being for illustrative purposes only.

The unit 14 includes a box-like frame 18 having upright supporting legs 20a, 20b, 20c, and 20d and cross-supporting braces 22 and 24a and 26 which are utilized to support the several components of the structure. The brushes are fed through the unit 14 in a linear path by conveyor means 30 mounted on frame 18 with the bristles facing generally upright relative to horizontal. The structure and operation of one suitable conveyor means 30 is explained and disclosed in the aforementioned co-pending Hazelton application.

Preferably the finishing accessories 12b includes motor means 32 for providing a source of power to drive a suitable drive train mechanism 33 for driving a finishing element which may be enclosed within a shield or housing 34. This invention is concerned with the finishing element or abrasive member 36 which might also be categorized as a sanding disc.

Abrasive member 36 includes a dish-like disc 37 which is circular in plan and has a generally tapered face 37a as best illustrated in FIGURES 2 and 3. In the preferred embodiment, the disc 37 is formed as a segment of the surface of a sphere to give it a convex configuration. In the preferred embodiment, the face is formed on a radius of 18 inches and the chord across the face is 12 inches. The tapered face 37a of the disc is coated with an abrasive material 38 which should be one suited for finishing paint brushes or similar articles, such as granular particles of nickel clad tungsten carbide, although other abrasive coatings may be suitable for this purpose.

An upstanding hub 40 is generally centrally positioned in the interior or concave side of disc 37 to provide a means for connecting the disc to a driven shaft 42, which may be directly or indirectly connected to motor 32, by fastening means 44. Thus as shaft 42 is rotated, the disc 37 will be rotated also as indicated by the arrows A in FIGURES 4 through 8. It has been found that driving the disc 37 at 1600 revolutions per minute is desirable for this brush finishing operation. Suitable structure for rotatably journalling a disc-like member and for connecting it for rotation with the shaft of a motor 32 is known, such mounting arrangements being well within the ability of one skilled in the art and therefore will not be described in detail herein.

FIGURES 4 through 8 diagrammatically illustrate the operation of the abrasive member. The axis of rotation of the disc is preferably aligned with the path of brush travel although it is possible that the axis may be laterally displaced therefrom. Each member 36 should be positioned so that it lies in a generally horizontal plane relative to the generally upright or vertical plane of linear movement of the brushes. If desired, the discs 37 may be canted slightly relative to horizontal. It is to be understood that as a general matter, the relative positioning of the extent of the bristles 16a of the brushes 16 should be generally transverse to the disc. The vertical orientation of the disc 37 relative to the brush bristles should be such that as the brush initially passes under the disc, the bristles will not engage the disc. As a general rule, the disc should be mounted so that the peripheral edge of the disc is slightly spaced from the free ends of the brush bristles.

As the brushes are fed in the direction indicated by the arrow B through the path 46, the rotation of each disc, as indicated by the arrow A, in combination with the configuration of the disc abrasive surface initially bends and fans the bristles 16a of the brushes outwardly generally in the direction of contour of the disc, as represented in FIGURES 4 and 6. The spacing of the disc so that the free ends of the bristles pass under the extreme peripheral edge of the disc supplements the bending and tapering action of the rotating disc. As the brush travels further, it gradually engages a portion of the surface of the disc which is of greater depth, and therefore extends deeper into the bristles. As the brush bristles engage this center portion of the convex disc, they are twisted and turned in an opposite direction so that they tend to generally pass under center at the axis of rotation of the disc. The bristles are then spread and fanned to the opposite side of the path of brush travel and gradually work their way back to alignment with the path of brush travel near the peripheral edge of the disc. Thus in one pass through one disc, both sides of the brush bristles are worked upon.

Where two discs 37 are mounted with the centers of rotation of the discs spaced on opposite sides of the path of brush travel, the brush generally tends to fan out in the direction of decreasing depth or contour of the face of the disc regardless of on which side of the path of travel the disc is positioned and regardless of the direction of rotation of the disc.

The abrasive element of this invention provides an abrasive surface which presents an area of increasing depth and contour relative to a brush fed past that surface in a generally linear path relative to the abrasive element. As the brush bristles are bent over and flared out, this action of flexing the brush bristles in combination with the rotation of the abrasive elements tends to generally expose the end portions of all of the bristles to the abrasive surface in such a fashion as will produce a. tapered contour to the free ends of the bristles. While the structure of the element is relatively simple, the results produced therewith are vastly superior to anything previously used in the brushmaking art for finishing the tapered or chisled configuration on the bristles of a brush.

The foregoing detailed description has been given for clearness of understandi'ng only, and no unnecessary limitations should be understood therefrom, as some modifications may be obvious to those skilled in the art.

I claim:

1. A brush finishing apparatus, comprising: means defining a supporting frame; means on said frame for feeding brushes in a path of travel through the frame; a disclike abrasive element mounted on said frame in a plane generally transverse to the plane of the bristles of brushes fed through said path of travel, said abrasive element having a generally convex bristle engaging surface coated with an abrasive material and mounted in the frame in a position for the bristle engaging surface to contact the free ends of brush bristles fed through said path of brush travel; and means on said frame for rotating said abrasive element.

2. The brush finishing apparatus of claim 1 wherein the abrasive element is mounted relative to the path of brush travel so that the free ends of the brush bristles are spaced from the periphery of the abrasive element in the direction of the extent of the brush bristles a distance less than the height of the curve of the convex bristle engaging surface.

3. The brush finishing apparatus of claim 1 wherein a pair of abrasive elements are rotatably mounted in the frame spaced from each other in the direction of the path of brush travel.

4. The brush finishing apparatus of claim 3 wherein one abrasive element is mounted for rotation on an axis laterally spaced to one side of the path of brush travel and the other abrasive element is mounted for rotation on an axis laterally spaced to the other side of the path of brush travel.

5. The brush finishing apparatus of claim 3 wherein each of said abrasive elements are rotated in the same direction.

6. The method of finishing the bristles of a brush to a generally tapered configuration, comprising: providing a disc-like abrasive surface having a curved convex configuration, feeding brushes across said curved surface in a path which progressively engages the bristles to varying depth and passes generally over the center of said surface and rotating said surface about a single fixed axis for spreading said bristles first in one direction and then in the opposite direction as the feed progresses across said curve of said surface.

7. The method of claim 6 wherein the brushes are fed in a generally linear path.

8. The method of claim 7 wherein the brushes are fed relative to the abrasive surface so that the bristle ends are spaced from the periphery of the abrasive surface a distance less than the height of the curve of the convex abrasive surface.

References Cited UNITED STATES PATENTS 2,435,320 2/1948 Metzger et al. 51-124 X 2,626,221 1/ 1953 Elliott.

2,854,797 10/1958 Van Clief 5l110 3,063,204 11/1962 Baumgartner 51-119 3,281,996 11/1966 Cuklanz.

FOREIGN PATENTS 1,019,782 11/1952 France.

HAROLD D. WHITEHEAD, Primary Examiner.

U.S. Cl. X.R. 5128l; 300-17 

